The mass and charge of one mole of electrons are, respectively:

1. 5.48 × ${10}^{-7}$ kg, 9.65 C, 
2. 5.48 × ${10}^{-7}$ C, 1.098 x 10²⁷
3. 5.48 × ${10}^{-7}$ kg, 9.65 × ${10}^4$ C
4. 9.65 × ${10}^4$ C, 1.098 x 10²⁷

The period in the modern periodic table indicates the value of :

1. Atomic number

2. Atomic mass

3. Principal quantum number

4. Azimuthal quantum number.

The number of orbitals indicated by the following set of quantum numbers, n = 3, l = 2, m =+2 is:

1.  1

2.  2

3.  3

4.  4

The maximum number of neutrons are present in the nuclei of

$1.$ ${\mathrm{O}}_8^{16}$
$2.$ ${\mathrm{Mg}}_{12}^{24}$
$3.$ ${\mathrm{Fe}}_{26}^{56}$
$4.$ ${\mathrm{Sr}}_{38}^{88}$

The complete symbol for the atom with the given atomic number (Z) and atomic mass (A) would be, respectively,

1.  ${}_4{}^9\mathrm{Be}$   ${}_{92}{}^{233}\mathrm{U}$     ${}_4{}^9\mathrm{Be}$

2.  ${}_{17}{}^{35}\mathrm{Cl}$    ${}_{92}{}^{233}\mathrm{U}$    ${}_4{}^9\mathrm{Be}$

3.  ${}_4{}^9\mathrm{Be}$    ${}_{17}{}^{35}\mathrm{Cl}$     ${}_{92}{}^{233}\mathrm{U}$

4. ${}_{92}{}^{233}\mathrm{U}$    ${}_4{}^9\mathrm{Be}$    ${}_{17}{}^{35}\mathrm{Cl}$

Yellow light emitted from a sodium lamp has a wavelength (λ) of 580 nm.

The frequency (ν) and wave number of this yellow light would be, respectively:

1. 517 x 10¹⁴ s^-1 , 172 x 10⁶ m^-1

2. 6.17 x 10¹⁴ s^-1 , 1.72 x 10⁶ m^-1

3. 4.17 x 10¹⁴ s^-1 , 2.72 x 10⁶ m^-1

4. 5.17 x 10¹⁴ s^-1 , 1.72 x 10⁶ m^-1

The energy of the photon with a frequency of 3×10¹⁵ Hz is :

1. 1.988 × ${10}^{-18}$ J
2. 1.588 × ${10}^{-18}$ J
3. 1.288 × ${10}^{-18}$ J
4. 2.988 × ${10}^{-18}$ J

A photon of wavelength 4 × 10^–7 m strikes a metal surface, the work function of the metal being 2.13 eV.  The kinetic energy of emission would be:
 
1.  0.97 eV
2.  97 eV 
3. 4.97 × ${10}^{-19}$ eV
4.  5.84 × 10⁵ eV

The correct comparison between energy required to ionize an H atom if the electron occupies n = 5 orbits and the ionization enthalpy of H atom ( energy required to remove the electron from n =1 orbit) would be -

1) More energy is required to ionize an electron in the 5th orbital of hydrogen atom as compared to that in the ground state

2) More energy is required to ionize an electron in the 8th orbital of hydrogen atom as compared to that in the ground state

3) Less energy is required to ionize an electron in the 5th orbital of hydrogen atom as compared to that in the ground state

4) Less energy is required to ionize a neutron in the 6th orbital of hydrogen atom as compared to that in the ground state

The wavelength of the light emitted when the electron returns to the ground state in the H atom, from n = 5 to n = 1, would be: (The ground-state electron energy is –2.18 × 10^-18 j) 
1. Wavelength = 9.498 x 10^-8 km
2. Wavelength = 12.498 x 10^-8 m
3. Wavelength = 9.498 x 10^-8 m
4. Wavelength = 9.498 x 10^-8 cm